They just mostly can't get it.
Tinfoil hat time. It's no secret that Americans in general seem to be getting more and more incapable of rational thought / critical thinking, and they seem a lot more poorly educated than previous generations of the same social class. (Not to mention the rest of the world.)
I don't think that's an accident.
Stupid people are a lot easier to herd than intelligent people. All you have to do is feed them a load of garbage, tell them what they should fear, and then convince them that you are the only one who can save them from these fears. If you've done your job well, they won't be capable of figuring things out for themselves and they'll believe you and follow you.
It shows up not just in politics. How many of those stupid made-up memes on Facebook are taken as fact by people who have no idea how to check the facts? It's not an accident that the fastest-spreading and most believed ones are those that feed into people's carefully cultivated fears and prejudices. They don't WANT to have them disproven. They will close their ears and eyes to science, logic, and evidence.
I don't understand.
An example - I've been trying to understand how anyone can believe that contrails are actually "chemtrails" meant by some nebulous group (usually the government) to poison us. You can give them all the science, all the data, and they won't listen. You can point out that if someone is actually doing what they think, those people are also poisoning themselves and their own children, and still no lightbulbs go on.
With the ability to search the internet, you'd think people would be able to check facts. But A.) they're too lazy to do it, and B.) when they do, they can't tell the difference between valid sources, screaming idiots, and bogus "news sources". So they just indiscriminately choose whatever source agrees with their prejudices, no matter where or who it comes from.
Watch the movie "Idiocracy". Do you see a parallel with the Trump candidacy?
It's getting darker and darker out there, and that scares me.
In earlier centuries, people were poisoned by lead. In makeup. In paint. Artists were especially susceptible, like Van Gogh and James McNeill Whistler. The lead tended to affect certain segments of the population. More recently, lead was in gasoline, the solder in food cans, water pipes, house paint, toothpaste tubes, and pesticides. Lead wasn't banned in paints in the US until 1978.
According to a footnote in a book I'm currently reading, "although lead has been removed from most consumer products, it continues to build up in the atmosphere because of industrial applications. The average person of today has about 625 times more lead in his system than someone of fifty years ago."** (Note, sources differ, see my footnote below.)
Anyway, in earlier centuries, only some people got lead overdoses. Now, everybody has very high lead levels. I wonder if that contributes to the general mental nightfall.
It's getting darker and darker out there.
I came across an interesting discussion of why the Japanese have so much difficulty with English, both in learning vocabulary and pronunciation. In English, we have letters that represent individual sounds. Given a written English word and the sounds of the letters, you can figure out (or approximate) how to pronounce that word. Given a spoken word, you can phonetically figure out how to (approximately) spell it.
In Japanese katakana (in simplest terms) it's even easier to figure out the pronunciation of a Japanese word, and how to spell it, but the problem is that there is no correspondence between the Roman alphabet and katakana. Katakana has five vowels and (I think) one consonant, and all of the remaining symbols represent syllables. For example, there is no katakana symbol for the sound of the letter "P" all by itself. The closest symbol is for a syllable like "pu". So katakana pronunciation guides for English words will have the learner pronouncing the final letter of the word "stop" as "pu". "Stopu". There's a good video on the topic at https://www.youtube.com/watch?v=fherVzjq20w
**Said book has an extensive bibliograpny, but no connection between the bibliography and the text (phooey!), so I have no idea where the author got that from. I did search a bit and found the "625 times more lead" in this book: https://books.google.com/books?id=agaOKrvAoeAC&pg=PA615&lpg=PA615&dq=lead+625+times+more&source=bl&ots=qAsmsKyldi&sig=i6nAxEEIyFEwlgmJla7vpJdArIM&hl=en&sa=X&ved=0ahUKEwj5raDptqPNAhWJWj4KHQriBBYQ6AEIJTAB#v=onepage&q=lead%20625%20times%20more&f=false
but it's significant that this reference says we have less lead since unleaded gasoline, but "625 times more" than a hundred years ago.